Activewear refers to attire or clothes designed for the purpose of transitioning from exercise wear to casual wear.
Activewear clothes are clothes that serve the purpose of an active life mixed with a casual social life, they can be used for exercising and then transitioning into casual wear.
Activewear clothes have more flexibility and style along with functionality and comfort.
Sportswear refers to clothes designed specifically for sports purposes.
Sportswear is sports-specific. A particular type of gear and clothes.
Sportswear clothes are less flexible and are more focused on comfort, functionality and thermal function of a fabric. They are very sports specific clothes for gymnastics or swimming. for eg: are absolutely different from any other type of clothes.